Simple disposable assay devices for the detection of an analyte in a liquid sample are well known. EP291194 discloses such a device comprising a porous flow through carrier wherein a labelled binding reagent is caused to interact with a liquid sample of interest and flow through the device. Detection of the labelled binding reagent at a downstream detection zone provides an indication of the amount or presence of analyte in the sample. Such devices require the sample to be in a liquid form in order to be able to pass through a porous matrix. Thus liquid samples such as urine may be used directly in such a device without further treatment. However, low viscosity, solid or semi-solid samples such as sperm or saliva, or samples taken from a throat swab may need to be diluted prior to use. Furthermore, the sample may need to be pre-treated with a fluid in order to expose the analyte of interest.
US20060024843 discloses a lateral flow assay device comprising an assay test strip in combination with a sample containing unit for detection of a sample of interest. The sample containing unit provides the ability to extract, dilute, or treat the sample in any other way before introducing it onto the test-strip. For this purpose, the unit may contain an extracting or diluting solution. Following a suitable incubation period, a seal separating the liquid from the test-strip is broken by rotation of the sample containing unit by the user.
U.S. Pat. No. 4,654,127 discloses a single use assay device comprising a fluid container comprising a test sample chamber and a separate chamber containing a calibrant fluid provided within first and second rupturable seal means wherein rupture of the seal means allows the calibrant fluid to flow to the assay means.
Many liquid containers include a liquid tight openable seal which may be opened to allow access to the liquid contained therein. Examples of such containers include drink cartons, cosmetics containers, pharmaceuticals containers, etc. The liquid-tight seal serves a number of useful functions such as retaining the liquid within the container and preventing or minimising evaporation of liquid. The seal may be removed by peeling it away at least partially to reveal the contents of the container. The seal may for example be in the form of a screw cap to be unscrewed by the user, or to be pressed down into the container in order to open it. Alternatively, as in the case of some drinks containers, the seal may be puncturable and punctured by use of a sharp implement such as a pointed straw in order to access the liquid contained therein.
U.S. Pat. No. 5,079,141 discloses a pre-filled and pre-sealed apparatus for carrying out chemical, particularly immunochemical, analyses. The apparatus comprises a test base containing therein wells, into which are introduced all the reagents necessary for performing the assay reaction in question. The apparatus further comprises a reagent stick having at one end a sharp reactive point onto which a sample to be assayed can be adsorbed. The base and wells are covered with an impervious foil layer which can easily be pierced with the sharp reactive end of the testing stick included in the apparatus.
Such fluid containers designed to be directly punctured by an item or sampling device typically have seals of low elasticity, which are punctured by applying mechanical force to insert a sampling device through the seal and into the liquid container. In order to minimise evaporation the seals may be a thick metal foil. However there are a number of drawbacks with this arrangement. For example, the user of the device may not have sufficient strength to puncture the seal due to the high puncture force required to force the sampling device through it. Alternatively, the user may thrust the sampling device into the test apparatus using inappropriately excessive force, thereby damaging the apparatus and/or device and/or causing liquid to be ejected from the container. In order to reduce the force required to pierce the foil, the foil may be made to be very thin or contain perforations or hairline grooves. However, this increases the chance that liquid may evaporate from the container, due to presence of pin-holes or that the seal is less robust. Direct insertion of the item through the seal also requires that the item to be inserted is sharp enough to pierce the seal. It is not always convenient to provide a sharp item, for example in the case wherein the item is a sampling device for insertion into a bodily orifice.